CAPE CANAVERAL, FL - NOVEMBER 26: In this handout provided by NASA, United Launch Alliance Atlas V rocket with the NASA's Mars Science Laboratory (MSL) Curiosity rover aboard clears the tower during launch at Space Launch Complex 41 at Cape Canaveral Air Force Station November 26, 2011 in Cape Canaveral, Florida. Sealed inside the rocket's protective payload fairing is NASA's Mars Science Laboratory (MSL) spacecraft, beginning a 9-month interplanetary cruise to Mars where it is designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source.. (Photo by Darrell L. McCall/NASA via Getty Images)

Photo: Nasa, Getty Images

CAPE CANAVERAL, FL - NOVEMBER 26: In this handout provided by NASA,...

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CAPE CANAVERAL, FL - NOVEMBER 26: In this handout provided by NASA, NASA Administrator Charles Bolden monitors the countdown of the United Launch Alliance (ULA) Atlas V rocket carrying NASA's Mars Science Laboratory (MSL) Curiosity November 26, 2011 at the ULA launch control center on Cape Canaveral Air Force Station in Cape Canaveral, Florida. Sealed inside the rocket's protective payload fairing is the MSL spacecraft, beginning a 9-month interplanetary cruise to Mars where it is designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. (Photo by Paul E. Alers/NASA via Getty Images)

Photo: Nasa, Getty Images

CAPE CANAVERAL, FL - NOVEMBER 26: In this handout provided by NASA,...

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NASA's Curiosity rover, formally known as the Mars Science Laboratory, heads for space on November 26, 2011 atop an Atlas 5 rocket from launch pad 41 at Cape Canaveral, Florida. The Mars Science Lab in expected to land on Mars early August 2012. AFP PHOTO/Bruce Weaver (Photo credit should read BRUCE WEAVER/AFP/Getty Images)

Crowds of people watch from Kelly Park on Merritt Island, Fla., to see the launch of the rover, Curiosity, from Cape Canaveral Air Force Station, Fla., on Saturday, Nov. 26, 2011. More than 13,000 invited guests jammed the Kennedy Space Center on Saturday morning to witness NASA's first launch to Mars in four years, and the first flight of a Martian rover in eight years. (AP Photo/Florida Today, Craig Rubadoux) NO SALES; MAGS OUT

With the roar of an Atlas 5 engine, NASA began its boldest venture yet to another planet, sending its Mars Science Laboratory on an eight-month journey that is expected to provide new and more detailed information about whether the red planet is - or ever has been - hospitable to life.

After being postponed by one day to replace a faulty battery, the launch went off flawlessly at 10:02 a.m. Saturday, the rocket rising on a column of white smoke.

The rocket's payload was the rover Curiosity, the largest and most sophisticated in a series of robotic vehicles that NASA has landed on Mars. Built at the Jet Propulsion Laboratory, Curiosity is a six-wheeled, 1 ton, car-size vehicle crammed full of sophisticated scientific gadgets.

Its mission, NASA officials stressed, is not to find life on Mars, but to find out whether life could have existed on Mars in the form of microbes, tiny organisms that are abundant on Earth. It also will try to find further evidence to suggest whether astronauts could survive on Mars.

"I like to say it's extraterrestrial real estate appraisal," Pan Conrad, a JPL astrobiologist, said at a briefing earlier last week.

NASA intends for the rover to spend one Martian year, which is about two Earth years, exploring an area called Gale Crater, which includes a gently sloped, 3-mile-high mountain made of sedimentary rock. As with prior missions, there is the likelihood that the rover will keep going after its two-year "warranty" expires.

Scientists hope that as the rover ascends the mountain, the rock will tell the geologic history of the area and ideally suggest whether it could have supported life.

"We're basically reading the history of Mars' environmental evolution," said John Grotzinger, the project's chief scientist.

To sustain life, scientists say, a planet needs three elements: water, energy and carbon. The first two have been established as existing on Mars, but previous missions have not allowed scientists to determine whether there is carbon.